Question

f(x)=x^2-1 and g(x)=2x-3 find (g o f)(5)
Help PLEASE :)

Answer 1

Find f(5), plug the answer into g(x)

Answer 2

what is f(5) if f(x)=x^2-1?

Answer 3

(g o f)(x)=g(f(x))

Answer 4

\[gof(x)=g(f(x))\]
we have
g(x)=2x-3
f(x)=x^2-1
so
\[gof(x)=2(x^2-1)-3\]
we get
\[gof(x)=2x^2-5\]
put x=5
\[gof(5)=2*5*5-5\]
we get
\[gof(5)=45\]

Answer 5

45 or -45?

Answer 6

45